Now my problem is in BF3 it randomly crashes, i've seen other threads and tried using msi afterburner to up the voltage to increase stability and it has helped but not completely recently i got a second and am running SLI now with better performance but the same crashes. I noticed that there is a option to force constant voltage, should this be enabled? is it possible even though i have the voltage set to 1025mv it still varies? i don't know if this is causing the crashes because i can't check MSI after its crashed because it locks up but just an idea i had.

You can try playing with the other card only and see if it crashes agains. Just to rule some things out. There's a solid chance this card is the issue, but still better be sure Force Constant Voltages is not recomended, but if it solves your problem, enable it. Won't hurt, AFAIK.